高层住宅小区给排水设计中的几点体会

介绍了深圳坪洲新村多栋高层住宅及地下一层停车库组成.工程概况、生活给水系统的选型、排水系统、消火栓系统的选型、水泵接合器的设置个数、室外消火栓的设置个数.     

谈高层民用建筑中室外消火栓的设置

就高层民用建筑消防设计中室外消火栓的设置问题进行了论述,从室外消火栓的设置场所、给水系统、选型、计算及水源等方面介绍了具体方法,以合理设置并消除故障。     

防火卷帘施工安装中有关问题

对施工安装中出现的防火卷帘选型、喷水护装置设置、手动应急机械操作功能设置、配电等方面存在的问题进行了分析和探讨。     

探讨桂电花江校区供水工程排气阀选型计算与设置

长距离、高扬程、大起伏输水工程的排气阀设置是保证管道安全运行的重要措施。但是国内相关规范对排气阀口径的设计方法比较笼统,美国相关标准对排气阀的选型计算有比较详细的规定,排气阀安装可参照美国相关标准进行选型计算与设置。对排气阀阀门井作了改进,增加通气效果。     

吉林漫江生态旅游综合开发温泉中心结构设计与分析

吉林漫江生态旅游综合开发温泉中心地上裙房6层,设置1层半地下室,主体结构高度31.6m,采用钢框架结构体系,不设置钢支撑。首先结合地质情况对项目地基基础部分的设计选型进行了介绍。随后,系统介绍了半地下室部分的结构选型和方案确定过程。同时,对上部结构选型和结构不规则控制措施进行了具体陈述。最后,对室内温泉区的大跨度钢结构屋面选型过程进行了重点介绍。研究及设计结果表明:通过选用合理的计算措施和设计措施,原结构选型合理,结构各项计算指标可以较好地满足规范要求,结构安全、可靠,结构设计可行。     

浅谈运用水表节水的措施

从合理设置水表位置、水表选型、提高计量准确性的技术措施等方面,阐述了民用建筑节水的有效技术措施,指出合理设置和使用水表对节水工作的重要性。     

谈漏电火灾报警系统应用的认识

本文阐述了漏电火灾报警系统的组成,设置的必要性,设置的原则以及设计方法。并就系统设计选型提出相关建议。     

谈市政给水加压泵房的设计

结合某水厂加压泵房的工程实例,主要对加压泵房的设计思路、计算方法以及水泵选型、进出水管件设置、起重机选型、真空设备等方面进行了介绍,同时结合运行情况,对一些常见的设计问题进行分析,并给出建议,以供参考。     

徐州市骆马湖水源地取水泵站水泵选型设计

以徐州市骆马湖水源地取水泵站工程为例,着重介绍水泵机组选型设计。工程通过更换叶轮大小、设置变频调速等方式满足不同工况的要求。详细介绍了设计过程,为以后类似大型取水工程水泵选型提供了借鉴。     

全面调试水力系统的平衡

全面水力平衡技术是解决空调、供热水系统平衡最为有效的方法，它包括： 1）水系统的正确设计。 2）通过专业的平衡阀选型计算软件，在设计阶段对平衡阀进行合理的选型与设置。     

Evaluation of surface characteristics of laminated flooring

In this study, surface characteristics of commercially manufactured laminated flooring were evaluated. The surface roughness of samples consisting of high-density fiberboard (HDF) base and melamine resin saturated paper overlay was investigated. Here, 10 cm×10 cm samples of two types of panels were used for the experiments. A fine stylus technique was employed for the measurements. Three roughness parameters, namely average roughness (_Ra$R_{\mathrm{a}}$), mean peak to valley height (_Rz$R_{\mathrm{z}}$), and maximum roughness (_Rmax$R_{\max }$) were considered to determine roughness of the flooring panels. It was found that statistically significant difference existed between two types of samples as well as values taken along and across the sandmarks of the HDF and overlaid panels. Average _Ra$R_{\mathrm{a}}$, _Rz$R_{\mathrm{z}}$, and _Rmax$R_{\max }$ values for HDF were found as 2.73, 26.04, and 27.27 μm, respectively. Overlaid samples resulted in 15.6%, 26.0%, and 21.0% lower values of above parameters than those of HDF panels.     

Effect of some parameters on the formation of chloroform during chloramination of aqueous solutions of resorcinol

The effects of various factors (N/Cl ratio used to prepare monochloramine, monochloramine doses, pH and contact time) on the monochloramine demand and on the chloroform yield during chloramination of resorcinol have been investigated. Chloramination experiments were carried out at 24 ± 1 °C, at pH values ranging from 6.5 to 12 using a bicarbonate/carbonate buffer and preformed monochloramine solutions prepared at pH 8.5 with N/Cl ratios ([NH₄Cl]₀/[Total free Cl₂]₀ ranging from 1.0 to 150 mol/mol). Kinetic experiments ([Resorcinol]₀ = 5 or 100 μM, [NH₂Cl]₀/[Resorcinol]₀ = 20 mol/mol, pH = 8.5 ± 0.1) showed a slow increase of the monochloramine consumption with reaction time. The monochloramine demands after reaction times of 7 days ([Resorcinol]₀ = 100 μM) and 14 days ([Resorcinol]₀ = 5 μM) were equal to 8.5 mol of NH₂Cl/mole of resorcinol and were higher than the chlorine demands (≈7.3 mol/mol). Chloroform yields from monochloramination of resorcinol were lower than 8% (<80 mmol of CHCl₃/mole of resorcinol) and were less than the yields obtained by chlorination (0.9-0.95 mol/mol). Chloroform productions increased with increasing monochloramine dose and reaction time and decreased with increasing pH values within the pH range 6.5-10. Chloroform formation markedly decreased when the N/Cl ratio increased from 1 to 1.5 mol/mol and was suppressed at N/Cl > 100 mol/mol. The data obtained in the present work suggest that free chlorine released from monochloramine hydrolysis plays a significant role on the formation of chloroform during chloramination of resorcinol at N/Cl ratios close to unity (1.0 < N/Cl < 1.5).     

Photochemical generation of reactive species upon irradiation of rainwater: Negligible photoactivity of dissolved organic matter

This paper focuses on the study of the photochemical activity of dissolved organic matter present in rainwater. Formation rates of the reactive species hydroxyl radical (OH^•), singlet oxygen (¹O₂) and dissolved organic matter triplet states (³DOM^?) were determined by irradiation (UV-A) of wet-only rainwater samples collected in Turin (Italy) in the presence of specific scavengers (benzene, furfuryl alcohol and phenol, respectively). Photo-formation rates of OH^• (≈ 3 · 10⁻¹¹ M s⁻¹) and ¹O₂ (≈ 10⁻¹⁴ M s⁻¹) were lower (1 or 2 orders of magnitude) or largely lower (4 to 10 orders of magnitude) than those determined for fog and cloud samples in previous studies. ³DOM^? formation rate values were either negligible or quite low (≈ 10⁻¹² M s⁻¹) by comparison with those evaluated for surface water samples. Deduced steady-state [OH^•] were in the same range as those reported for fog samples in the literature (8.7 · 10⁻¹⁶ to 1.5 · 10⁻¹⁵ M), while [¹O₂] was often several orders of magnitude lower and, therefore, could be considered as negligible. Nitrite (NO₂⁻) constituted the main source of OH^• (69 ± 21 to 138 ± 36%), and the deduced contribution of DOM was low or nil. All the results obtained in this study tend to demonstrate that DOM (including HUmic LIke Substances, HULIS) present in rainwater is poorly or not photoactive. Therefore, there could be considerable difference between rainwater DOM (HULIS included) and the organic matter present in surface waters, particularly the humic substances, as far as the photochemical activity is concerned.     

Enhanced ignition of biomass in presence of NOx

Accumulation of combustible biomass residues on hot surfaces of processing machineries can pose fire hazards. In addition, the presence of nitrogen oxides (NO_x) from plant equipment alters the local conditions, aggravating the propensity for low temperature ignition risks. This study presents an experimental study on a relative effect of NO_x on ignition temperature of morpholine, an important surrogate of biomass, to reveal the sensitising role of NO_x in ignition of biomass fuels and to gain mechanistic insights into the chemical aspect of this behaviour in fire. The experiments employed a flow-through tubular reactor, operated at constant pressure and residence time of 1.01 bar and 1.0 s, respectively, and coupled with a Fourier-transform infrared spectroscope. For a representative fuel-rich condition (Φ=1.25), the concentration of NO_x as small as 0.06% lowers the ignition temperature of morpholine by 150 °C, i.e., from approximately 500 °C to 350 °C. The density functional theory (DFT) calculations performed with the CBS-QB3 composite method, that comprises a complete basis set, characterised the dynamics and energies of the elementary nitration reactions. We related the observed reduction in ignition temperature to the formation of unstable nitrite and nitrate adducts, as the result of addition of NO_x species to morphyl and peroxyl radicals. Furthermore, the reaction of NO_x with low-temperature hydroperoxyl radical leads to the formation of active OH species that also propagate the ignition process. The present findings quantify the ignition behaviour of biomass under NO_x–doped atmospheres. The result is of great importance in practical applications, indicating that safe operation of wood-working plants requires avoiding trace concentration of NO_x within the vicinity of biomass residues. This can be facilitated by proper (and separate) venting of engine exhausts.     

Modeling the effect of immobilization of microorganisms on the rate of biodegradation of phenol under inhibitory conditions

The main objective of this research is to model the effect of biodegradation process of phenol at high initial concentrations using a well known immobilization technique of the biomass. This work focused on testing the effect of activated carbon and clay while considering the diffusive internal mass transfer limitations. Biodegradation of phenol was performed by using enriched microorganisms from a compost of agricultural wastes. The average phenol biodegradation rate (uptake) of free biomass system was 235.3 mg g⁻¹ h⁻¹ at initial concentration range of 212-260 mg/L. However, the values for the systems of immobilized biomass in alginate and activated carbon (1 mm), alginate, activated carbon (4 mm), alginate, activated carbon and clay (1 mm) and alginate, activated carbon and clay (4 mm) were 64.9, 27.6, 27.5, and 8 mg g⁻¹ h⁻¹ respectively. The effective diffusion factors in different matrix were obtained using an intra-particle diffusion-based mathematical model. Diffusion limitation was observed when the matrix contained clay in addition to activated carbon. The diffusion coefficient was decreased from 1.6 × 10⁻⁸ to 1.2 × 10⁻⁹ cm²/s when clay was added to the matrix of 1 mm of alginate and activated carbon. Also, slight differences between the diffusion factors were observed for larger beads. The combination of clay and AC contributes to better mineralization of phenol at high concentrations. This could be attributed to the synergism of both additives.     

Determination of sorption of seventy-five pharmaceuticals in sewage sludge

Sorption of 75 active pharmaceutical ingredients (APIs) to three different types of sludge (primary sludge, secondary sludge with short and long sludge age respectively) were investigated. To obtain the sorption isotherms batch studies with the APIs mixture were performed in four nominal concentrations to water containing 1 g of sludge. The range of APIs concentrations was between ng L⁻¹ to μg L⁻¹ which are found in the wastewater effluents. Isotherms were obtained for approximately 45 of the APIs, providing distribution coefficients for linear (K_d), Freundlich (K_f) and Langmuir (K_L) isotherms. K_d, K_f and K_L ranging between 7.1 × 10⁴ and 3.8 × 10⁷, 1.1 × 10⁻² and 6.1 × 10⁴ and 9.2 × 10⁻³ and 1.1 L kg⁻¹, respectively. The obtained coefficients were applied to estimate the fraction of APIs in the water phase (see Abstract Graphic). For 37 of the 75 APIs, the predicted presence in the liquid phase was estimated to >80%. 24 APIs were estimated to be present in the liquid phase between 20 and 80%, and 14 APIs were found to have <20% presence in the liquid phase, i.e. high affinity towards sludge. Furthermore, the effect of pH at values 6, 7 and 8 was evaluated using one way ANOVA-test. A significant difference in K_ds due to pH changes were found for 6 of the APIs (variation 10-20%).     

Reconsideration of the settlement behavior of peat from view point of hydraulic conductivity

This paper deals with the settlement of peat from the view point of hydraulic conductivity (k). The validity of using the oedometer tests, including the calculation method, for measuring k is carefully examined by numerical analysis as well as a test combined with an oedometer and a hydraulic conductivity test. It is found from these studies that the conventional oedometer test (JIS A 1217, 2009) can be evaluated to measure k for peat with the same accuracy as that for usual clays, provided that the incremental load ratio is unity. The significant difference in the characteristics of k for peat and usual clayey soils is their relation between the compression index (C_c) and the hydraulic conductivity change index (C_k). As a result, rather than remaining constant during consolidation, the coefficient of consolidation (c_v) of peat decreases considerably with increasing consolidation pressure (p), while the c_v coefficient for usual clayey soil is almost constant at the normally consolidated stage. The influence of c_v dependent on p is studied by a numerical analysis for the one dimensional consolidation problem as well as for the ground improved by vertical drain. It is found that if the incremental consolidation pressure (Δp/p) is large, careful judgment is required when adopting conventional consolidation analyses, especially in case of the vertical drain.     

最大动态剪力模数次增加率之预测

正规化最大动态剪力模数次增加率Ｎ＿ｇ之观念虽然已被提出，但是其影响因素之精确指标仍待后人研究。因此，本文深入探讨粘性土壤在现场有效覆土压力长期作用下，时间效应对最大动态剪力模数Ｇ＿（ｍａｘ）之影响，并与剪力波速回归公式作比较，以期达到预测Ｎ＿ｇ值之目标。在一般物理性质对时间效应之影响研究中，Ｎ＿ｇ值有随塑性指数Ｉ＿ｐ值增加之趋势，而平均颗粒粒径Ｄ＿（５０）愈小时，Ｎ＿ｇ值愈大，且重模试体之Ｎ＿ｇ值较原状试体为小。由本文之Ｎ＿ｇ－Ｉ＿ｐ－Ｃ值之关系可知，粘土含量Ｃ相同时，若Ｉ＿ｐ值愈大，则Ｎ＿ｇ愈大。而Ｎ＿ｇ－Ｉ＿ｐ－Ｃ＿ａ值三者之关系中，若二次压缩指数Ｃ＿ａ值相同，则Ｉ＿ｐ值愈大时，Ｎ＿ｇ值愈大。     

Evaluation of hydro-mechano-chemical behaviour of bentonite-sand mixtures

Bentonite-sand mixtures are widely used in engineering barrier of deep geological disposal of high-level radioactive nuclear waste and anti-seepage barrier of civil geotechnical engineering. Under the action of groundwater solution infiltration and external stress, the hydro-mechanical (HM) behaviour of bentonite-sand mixtures, i.e. the swelling characteristics and permeability, will change. Once the anti-seepage and filtration effect is weakened or lost, the pollutants will spread to the biosphere. Therefore, it is necessary to study the swelling characteristics and permeability of bentonite-sand mixtures under coupled mechano-chemical (MC) effect and to establish corresponding prediction model. For this reason, swelling tests under salt solution with different concentrations are conducted on pure bentonite and its mixtures with 30%, 70% and 90% sand contents, the compression tests are carried out on saturated samples, and the saturated permeability coefficient k of the sample under each load is calculated by Terzaghi's one-dimensional consolidation theory. The concepts of true effective stress p_e, montmorillonite void ratio e_m and critical sand content α_s are introduced to determine the e_m-p_e relationship and finally the k-e_m relationship of bentonite-sand mixtures. It is found that when the sand content α ≤ α_s, the e_m-p_e relationship of the mixture is linear and independent of the salt solution concentration, and when α > α_s, the e_m-p_e relationship of bentonite-sand mixture is bi-linear with the true effective deviatoric stress p_esα as the intersection. In addition, the e_m-k relationship also shows the linear trend when α ≤ α_s, and the slope of the line increases with the increase of the salt solution concentration. When α > α_s, the k-e_m relationship will deviate from the linear relationship. Moreover, the larger the sand content is, the farther the deviation is. On the basis of summing the regularity, a model for predicting the HM behaviour of bentonite-sand mixture under the coupled MC effect is proposed. By comparing the swelling and permeability test results with model prediction results of different types of bentonite and its sand mixtures, the predictive model is verified. The study on the HM behaviour of bentonite-sand mixtures under salt solution infiltration and the model establishment can provide experimental and theoretical basis for the design and construction of anti-seepage engineering by bentonite-sand mixtures.     

Evaluation of strategies for anaerobic bioremediation of high concentrations of halomethanes

Bioremediation is being considered for groundwater at an industrial site contaminated with carbon tetrachloride (CT), trichlorofluoromethane (CFC-11), and chloroform (CF), at concentrations typically considered too high for biological treatment. 1,1-Dichloroethene is also present. The objective of this study was to evaluate in situ anaerobic remediation by biostimulation alone (lactate, emulsified vegetable oil, and corn syrup), biostimulation (corn syrup) supplemented with vitamin B₁₂ (cyanocobalamin), and bioaugmentation in combination with catalytic levels of B₁₂. Three cultures were evaluated for enhancing biotransformation of CT, CFC-11 and CF: two were sulfate reducing enrichments (grown on lactate and ethanol, respectively), based on a high concentration of sulfate in the groundwater; the other was a fermentative enrichment grown on corn syrup. A microcosm study with soil and groundwater (neutralized to pH 7) from the site revealed that bioaugmentation is a potentially feasible treatment approach, with complete biotransformation of 8.8 mg/L CT, 26 mg/L CFC-11, and 500 mg/L of CF in approximately 500 days. The lactate-grown sulfate reducing culture and the corn syrup-grown fermentative culture were the most effective. Subsequent bioaugmentation with a chloroethene-respiring culture yielded rapid reduction of 1,1-dichloroethene (9.1 mg/L) to ethene. Complete transformation of CT, CFC-11 and CF was also observed with corn syrup + B₁₂, although the time required was twice as long compared to bioaugmentation. In the presence of B₁₂, biotransformation of [¹⁴C]CT and [¹⁴C]CF yielded mainly CO, CO₂, and organic acids. CT was consistently transformed first, followed by CFC-11 and then CF. Corn syrup was only partially effective for halomethane removal without B₁₂, but was more effective than emulsified vegetable oil or lactate.